Starch is composed primarily of two components: amylose, a mainly linear polymer of about 500-6000 .alpha.-D glucosyl residues, and amylopectin, a highly branched polymer of .alpha.-D glucosyl distributed in 15-60 residues per chain (Godet et al., Carbohydrate Polymers 27:47-52 (1995)). It is well known that amylose can form complexes with molecules such as iodine, alcohols and lipids, whereas amylopectin forms these complexes weakly or not at all (Morrison et al., Cereal Chem 70:385-91 (1993); Sarko & Zugenmaier, Fiber Diffraction Methods, A. D. French & K. C. Gardner, Eds., ACS Symposium Series 141:459-482 (1980)). The in situ biosynthesis of amylose-lipid complexes in starch with naturally occurring fatty acids and phospholipids has been demonstrated (Morrison et al. (1993)). Others have shown that complex formation occurs during heat/moisture treatments, especially during gelatinization of starches with naturally containing lipids (Kugimiya et al., Stake 32:265-270 (1980); Kugimiya & Donovan, J. Food Sci. 46:765-777 (1981)) or when lipids are added to defatted starches (Biliaderis et al., Food Chem. 22:279-295 (1986)) or pure amylose which is free of natural lipids (Biliaderis et al, Carbohydr. Polym. 5:367-389 (1985)).
Both naturally-occurring and heat-formed complexes show specific properties such as a decrease in amylose solubility or an increase in gelatinization temperatures (Eliasson et al., Stake 33:130 (1981), Morrison et al. (1993)). Polar lipids, e.g., fatty acids and their monoglyceride esters are of technological importance in starch systems, as they cause a reduction in stickiness, improved freeze-thaw stability (Mercier et al., Cereal Chem. 57:4-9 (1980) and retardation of retrogradation. One important example is the use of fatty acids and monoglycerides as anti-staling agents in bread and biscuits. Incorporation of such additives in the dough induces a slower crystallization (retrogradation) of the amylose fraction and retards the staling of bread (Krog, Stake 22:206-210 (1971)).